Smart polishing media assembly for planarizing substrates

ABSTRACT

A smart polishing media assembly is provided, along with a polishing system and a method for using the same. In one embodiment, the smart polishing media assembly includes a memory device coupled to a polishing material. The polishing material may be in pad, web or belt form. The memory device generally stores at least one material information, historical use information, and/or conditioning information of the polishing material.

BACKGROUND OF THE DISCLOSURE

1. Field of the Invention

Embodiments of the invention generally relate to a polishing media assembly for use in a chemical mechanical polishing system.

2. Background of Invention

In semiconductor wafer processing, the use of chemical mechanical planarization, or CMP, has gained favor due to the enhanced ability to increase device density on a semiconductor workpiece, or substrate, such as a wafer. As the demand for planarization of layers formed on wafers in semiconductor fabrication increases, the requirement for greater system (i.e., process tool) throughput with less wafer damage and enhanced wafer planarization has also increased.

CMP systems generally include a polishing head and a polishing material disposed on a platen. A substrate retained in the polishing head is pressed against the polishing material and moved relative to the polishing material in the presence of a polishing fluid. Abrasives, typically contained in the polishing fluid and/or polishing material, remove material from the surface of the substrate synergistically with the chemical activity provided by the polishing fluid.

Conventional polishing material is generally comprised of a foamed polymer, such as polyurethane. Conventional polishing materials are generally available in the form of circular pads or in a linear form, such as a web or belt. The web or belt is periodically advanced over the course of polishing a number of substrates as the polishing surface of the web is consumed by the polishing process. Alternatively, the web or belt may be continuously advanced or moved back and forth during processing.

Polishing materials generally wear during polishing, causing the surface of the polishing material to lose the ability to adequately retain polishing fluid during the polishing process, resulting in a non-uniform distribution of polishing fluid across the polishing material. A non-uniform distribution of polishing fluid may result in variations of removal rates across the substrate surface and inhibit uniform polishing of a substrate surface. To maintain uniform polishing results, the polishing material is periodically conditioned, cleaned, or advanced across the platen after polishing one or more substrates, thereby refreshing the portion of the polishing surface in contact with substrate during processing to maintain good processing results.

As the polishing material may be removed from the polishing system before fully consumed, or reused after an interruption in processing, it is critical to preserve the historical information regarding the prior use of the polishing material in order to prevent substrate damage and defect generation. For example, it may be undesirable to utilize polishing material that was used to polish one material, such as conductive material, for later used to polish another material, such as an insulating material. Furthermore, it may be undesirable to use different polishing fluids on the same polishing material to prevent cross-talk between polishing fluids, which may lead to undesired polishing results. Additionally, information regarding the number of times that a polishing material has been utilized and/or conditioned is critical to prevent the start of a polishing process without enough material life or length remaining to complete substrate polishing process. Moreover, as the polishing material may be transferred between tools, it would be advantageous for information associated with the polishing material to remain with the polishing material.

Therefore, there is a need for polishing material which can communicate with a processing system.

SUMMARY OF INVENTION

Embodiments of the invention generally include a smart polishing media assembly having a memory device, a polishing system in communication with the smart polishing media assembly, and methods for using the same. In one embodiment, the smart polishing media assembly includes a polishing material and a memory device coupled to the polishing material.

In another embodiment, the apparatus includes a polishing station, a polishing material disposed in the polishing station, a memory device coupled to the polishing material, and a computer based controller adapted to communicate with the memory device.

In yet another embodiment, the method for using a smart polishing media assembly includes reading information from a memory device coupled to a polishing media disposed in a polishing station, and polishing a substrate placed in contact with the polishing material. In other embodiment, historical processing information may be written to the memory device.

BRIEF DESCRIPTION OF DRAWINGS

So that the manner in which the above recited features of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

FIG. 1 depicts a plan view of one embodiment of a chemical mechanical planarization system of the invention;

FIG. 2 depicts a sectional view of one embodiment of a polishing station;

FIG. 3A depicts an end view of one embodiment of a memory device embedded in a core according to the present invention;

FIG. 3B depicts a side view of one embodiment of a memory device embedded in a core according to the present invention;

FIG. 4 depicts a cross section view of another embodiment of a memory device embedded in a polishing media assembly according to the present invention; and

FIG. 5 depicts a cross section view of yet another embodiment of a memory device embedded in a polishing media assembly on a platen according to the present invention.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

It is to be noted, however, that the appended drawings illustrate only exemplary embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

DETAILED DESCRIPTION OF INVENTION

The invention will be described below in reference to a planarizing process and a polishing material that can be performed on a chemical mechanical polishing system, such as a REFLEXION® CMP System available from Applied Materials, Inc., located in Santa Clara, Calif. Although the polishing process and composition described herein is illustrated utilizing the REFLEXION® CMP System, any system enabling chemical mechanical polishing and/or electrochemical mechanical processing using the methods or polishing material described herein can be used to advantage.

FIG. 1 depicts a plan view of one embodiment of a chemical mechanical planarization system 100 generally having a factory interface 102, a loading robot 104, and one or more polishing modules 106. Generally, the loading robot 104 is disposed proximate the factory interface 102 and the polishing module 106 to facilitate the transfer of substrates 122 therebetween. The polishing module 106 generally includes at least one polishing station 132 configured to planarize a substrate processed thereon. Some examples of suitable polishing stations are described in U.S. Pat. No. 6,244,935, U.S. Pat. No. 5,733,574, U.S. patent application Ser. No. 10/941,060 filed on Sep. 14, 2004, among others, all of which are hereby incorporated by reference.

A computer based controller 190 is connected to the polishing system 100 for instructing the system to perform one or more processing steps on the system, such as polishing a substrate or transferring a substrate in the polishing system 100. In one embodiment, the invention may be implemented as a computer program-product for use with a computer system or computer based controller 190. The programs defining the functions of an embodiment can be provided to a computer via a variety of signal-bearing media and/or computer readable media, which include but are not limited to, (i) information permanently stored on non-writable storage media (e.g., read-only memory devices within a computer such as read only CD-ROM disks readable by a CD-ROM or DVD drive; (ii) alterable information stored on a writable storage media (e.g., floppy disks within diskette drive or hard-disk drive); or (iii) information conveyed to a computer by communications medium, such as through a computer or telephone network, including wireless communication. Such signal-bearing media, when carrying computer-readable instructions that direct the functions of the invention, represent alternative embodiments of the present invention.

The factory interface 102 generally includes a cleaning module 116 and one or more substrate cassettes 118. An interface robot 120 is employed to transfer substrates 122 between the substrate cassettes 118, the cleaning module 116 and an input module 124. The input module 124 is positioned to facilitate transfer of substrates 122 between the polishing module 106 and the factory interface 102 by the loading robot 104. For example, unpolished substrates 122 retrieved from the cassettes 118 by the interface robot 120 may be transferred to the input module 124 where the substrates 122 may be accessed by the loading robot 104 while polished substrates 122 returning from the polishing module 106 may be placed in the input module 124 by the loading robot 104. Polished substrates 122 are typically passed from the input module 124 through the cleaning module 116 before the factory interface robot 120 returns the cleaned substrates 122 to the cassettes 118. An example of such a factory interface 102 that may be used to advantage is disclosed in U.S. Pat. No. 6,361,422, issued Mar. 26, 2002, which is hereby incorporated by reference.

The loading robot 104 is generally positioned proximate the factory interface 102 and the polishing module 106 such that the range of motion provided by the robot 104 facilitates transfer of the substrates 122 therebetween. An example of a loading robot 104 is a 4-Link robot, manufactured by Kensington Laboratories, Inc., located in Richmond, Calif.

The exemplary loading robot 104 has an articulated arm 126 having a rotary actuator 128 at its distal end. An edge contact gripper 130 is coupled to the rotary actuator 128. The rotary actuator 128 permits the substrate 122 secured by the gripper 130 to be oriented in either a vertical or a horizontal orientation without contacting the feature side of the substrate 122 and possibly causing scratching or damage to the exposed features. Additionally, the edge contact gripper 130 securely holds the substrate 122 during transfer, thus decreasing the probability that the substrate 122 will become disengaged. Optionally, other types of grippers, such as electrostatic grippers, vacuum grippers and mechanical clamps, may be substituted.

The polishing module 106 may be any suitable device for planarizing a substrate on a polishing material, including those that use polishing pads, polishing belts, polishing webs, or a combination thereof. Other systems that benefit from the systems include moving a substrate relative a polishing surface in a rotational, linearly or in other motion within a plane. As noted above, the polishing modules may be utilized in an electrochemical mechanical polishing system in which a substrate is processed by electrochemical dissolution concurrently with mechanical polishing. One such electrochemical mechanical process is described in U.S. patent application Ser. No. 10/941,060 filed Sep. 14, 2004, which is hereby incorporated by reference.

The exemplary polishing module 106 has a transfer station 136, a plurality of polishing stations 132 and a carousel 134 disposed on an upper or first side 138 of a machine base 140. In one embodiment, the transfer station 136 comprises at least an input buffer station 142, an output buffer station 144, a transfer robot 146, and a load cup assembly 148. The loading robot 104 places the substrate 122 onto the input buffer station 142. The transfer robot 146 has two gripper assemblies, each having pneumatic gripper fingers that grab the substrate 122 by the substrate's edge. The transfer robot 146 lifts the substrate 122 from the input buffer station 142 and rotates the gripper and substrate 122 to position the substrate 122 over the load cup assembly 148, then places the substrate 122 down onto the load cup assembly 148. An example of a transfer station that may be used to advantage is described in U.S. Pat. No. 6,156,124, issued Dec. 5, 2000, which is hereby incorporated by reference.

The carousel 134 is centrally disposed on the base 140. The carousel 134 typically includes a plurality of arms 150, each supporting a polishing head assembly 152. Two of the arms 150 depicted in FIG. 1 are shown in phantom such that a polishing surface 131 of one of the polishing stations 132 and the transfer station 136 may be seen. The carousel 134 is indexable such that the polishing head assemblies 152 may be moved between the polishing stations 132 and the transfer station 136. One embodiment of a suitable carousel is generally described in the previously incorporated U.S. Pat. No. 5,804,507.

Generally, a planarization process is performed at each polishing station 132. The planarization process may be a chemical mechanical planarization process, an electrochemical mechanical planarization process or other planarization process employing a pad or a web of polishing material to process a substrate thereon. A conditioning device 182 is disposed on the base 140 adjacent each polishing station 132. The conditioning device 182 periodically conditions the polishing surface 131 to maintain uniform polishing results.

FIG. 2 depicts a sectional view of the polishing head assembly 152 supported above the polishing station 132. The polishing head assembly 152 generally includes a drive system 202 coupled to a polishing head 204. The drive system 202 generally provides rotational motion to the polishing head 204. The drive system 202 is coupled to a carrier 208 that translates upon a rail 210 disposed in the arm 150 of the carousel 134. A ball screw or other linear motion device 212 couples the carrier 208 to the carousel 134 and positions the drive system 202 and polishing head 204 along the rail 210.

In one embodiment, the polishing head 204 includes a housing 214 having an extending lip 216 that defines a center recess 218 in which is disposed a bladder 220. The bladder 220 may be comprised of an elastomeric material or thermoplastic elastomer such as ethylene propylene, silicone and HYTREL™ polymer. The bladder 220 is coupled to a fluid source (not shown) such that the bladder 220 may be controllably inflated or deflated. The bladder 220, when in contact with the substrate 122, retains the substrate 122 within the polishing head 204 by deflating, thus creating a vacuum between the substrate 122 and the bladder 220. A retaining ring 224 circumscribes the polishing head 204 to retain the substrate 122 below the polishing head 204 while polishing. In another embodiment, the polishing head 204 is a TITAN HEAD™ substrate carrier manufactured by Applied Materials, Inc., Santa Clara, Calif.

The polishing station 132 generally includes a platen 230 that supports a polishing material 252. The platen 230 is typically comprised of aluminum. The platen 230 is supported above the base 140 by a bearing 238 so that the platen 230 may rotate in relation to the base 140. An area of the base 140 circumscribed by the bearing 238 is open and provides a conduit for the electrical, mechanical, pneumatic, control signals and connections communicating with the platen 230.

Conventional bearings, rotary unions and slip rings (not shown) are provided such that electrical, mechanical, pneumatic, control signals and connections may be coupled between the base 140 and the rotating platen 230. The platen 230 is typically coupled to a motor 232 that provides the rotational motion to the platen 230.

A polishing material 252 is disposed on the platen 230 and defines the polishing surface 131. The polishing material 252 may be in the form of a pad, a belt or a web. The polishing surface 131 of the polishing material 252 may be a dielectric or conductive material. The polishing material 252 may include grooves, embossments, texturing and/or perforations. In the embodiment depicted in FIG. 2, the polishing material is a web that may be advanced across the platen 230.

The platen 230 has an upper portion 236 that supports the polishing material 252. A top surface 260 of the platen 230 contains a center recess 276 extending into the top portion 236. The top portion 236 may optionally include a plurality of passages 244 disposed adjacent to the recess 276. The passages 244 are coupled to a fluid source (not shown). Fluid flowing through the passages 244 may be used to control the temperature of the platen 230 and the polishing material 252 disposed thereon. The polishing material 252 may be releasably fixed by adhesives, vacuum, mechanical clamps or by other holding methods to the platen 230.

A process fluid delivery system 290 may be disposed adjacent the platen 230. The process fluid delivery system 290 includes a nozzle or outlet 286 coupled to an process fluid source 292. The outlet 286 flows process fluid, such as electrolyte, from the process fluid source 292 onto the surface of the polishing material 252. Alternatively, it is contemplated that the process fluid may be delivered from other portion of the system, such as through the platen 230 and the polishing material 252.

A sub-pad 278 and a sub-plate 280 are disposed in the center recess 276. The sub-pad 278 is typically a polymeric material, such as polycarbonate or foamed polyurethane. Generally, the hardness or durometer of the sub-pad may be chosen to produce a particular polishing result. The sub-pad 278 generally maintains the polishing material 252 parallel to the plane of the substrate 122 held in the polishing head 204 and promotes global planarization of the substrate 122. The sub-plate 280 is positioned between the sub-pad 278 and the bottom of the recess 276 such that the upper surface of the sub-pad 278 is coplanar with the top surface 260 of the platen 230.

Both the sub-pad 278 and the sub-plate 280 optionally contain a plurality of apertures (not shown). A vacuum port 284 is provided in the recess 276 and is coupled to an external pump 282. When a vacuum is drawn through the vacuum port 284, the air removed between the polishing material 252 and the sub-pad 278 causes the polishing material 252 to be firmly secured to the sub-pad 278 during polishing. One example of such polishing material retention system is disclosed in U.S. Pat. No. 6,491,570, which is hereby incorporated by reference.

Optionally, to assist in releasing the polishing material 252 from the sub-pad 278 and platen 230 prior to advancing the polishing material 252, surface tension caused by fluid that may be disposed between the sub-pad 278 and the polishing material 252, a blast of fluid may be provided through the vacuum port 284 or other port (not shown) into the recess 276 by the pump 282 (or other source). The fluid within the recess 276 moves through the apertures (not shown) disposed in the sub-pad 278 and sub-plate 280 and lifts the polishing material 252 from the sub-pad 278 and the top surface 260 of the platen 230. The polishing material 252 rides upon the cushion of fluid such that it may be freely indexed across the platen 230.

In one embodiment, the polishing material 252 is part of a polishing media assembly 274. The polishing media assembly 274 includes a memory device 298 for providing information relating to the polishing material 252. In the embodiment depicted in FIG. 2, the polishing media assembly 274 is configured as a supply roll 240 that contains at least a portion of the polishing material 252 wound on a core 296. The polishing material 252 is fed from the supply roll 240 over a roller 242 and across the top surface 260 of the platen 230 to a roller 246. The polishing material 252 is fed over the roller 246 to a take-up roll 248 disposed to the opposite side of the platen 230.

The supply roll 240 is removably coupled to the platen 230 to facilitate loading another supply roll containing different polishing material. The supply roll 240 may be replaced once the polishing material 252 is consumed over the course of polishing a number of substrates or for other reasons. The supply roll 240 is coupled to a slip clutch 250 or similar device that prevents the polishing material 252 from inadvertently unwinding from the supply roll 240. After processing, the polishing material 252 may be rewound on the supply roll 240 for removal from the polishing station 132.

The memory device 298 is utilized to store information relating to the polishing material 252. In one embodiment, the memory device 298 is a read/writable chip. Information that may be written to, and/or read from the memory device 298 includes polishing material type, unused or remaining length, conditioning information, historical use information, thickness, diameter, unique identification code and the like. Conditioning information may include the number of times the material has been conditioned, which portions of the material has been conditioned, the type of conditioner used (i.e., brush, diamond, etc.), conditioning downforce, conditioner, RPM, conditioner sweep information, conditioning and fluids used and among others. Historical use information may include the numbers of substrate being polished, the polishing fluid used thereon, type of materials polished on the substrate, polishing recipes used (platen/head RPM), head sweep and substrate downforce, and among others. In another embodiment, the memory device 298 is a computer writeable and readable chip that can be remotely read and/or written by a computer based controller, such as the controller 190 described in FIG. 1.

The take-up roll 248 generally is removably coupled to the platen 230 to facilitate removal of used polishing material 252 that is wound thereon. The take-up roll 248 is coupled to a tensioning device 262 that keeps the polishing material 252 taunt between the supply roll 240 and take-up roll 248.

The polishing material 252 is advanced between the supply roll 240 and take-up roll 248 by a driver 266. In one embodiment, the driver 266 comprises a drive roller 268 and an idler 270 that pinches the polishing material 252 therebetween. The drive roller 268 generally is coupled to the platen 230. The drive roller 268 is connected to a controlled motor such as a stepper and an encoder 294 (as shown in phantom). The encoder 294 detects a metric indicative of the length of polishing material advanced across the driver roller 268 that corresponds to an amount of linear displacement of the polishing material across the platen 230. The encoder 294 may be a rotary encoder, a proximity sensor, an optical sensor, a linear displacement transducer or other sensor for detecting a length of polishing material as the polishing material 252 advances. Alternatively, the encoder 294 may be positioned to detect rotation of the rollers 242, 246 having a polishing material running thereover to determine the amount of polishing material advanced.

The driver 266 enables a predetermined length of polishing material to be pulled off the supply roll 240 by drive roller 268 as the drive roller 256 is controllably rotated. The predetermined length is usually about 1 inch or less, such as about ¼ inch indexing between substrates. A corresponding length of polishing material is wound on the take-up roll 248 as the polishing material 252 is advanced across the platen 230. The roll of polishing material 252 is about 100 feet in length, which allows for about 5000 or more substrates to be polished as compared to prior art polishing pads which often have to be replaced after 600 to 1000 substrates are polished.

A sensor 288 for detecting the diameter of the polishing material wound on the take-up roll 248 is typically coupled to the platen 230. The sensor 288 detects the surface of the polishing material such that as the polishing material advances, a chance in the diameter of the polishing material disposed the take-up roll 248 may be detected. It is contemplated that other types of sensors may be utilized to provide and detect different information as needed. The sensor 288 may also provide surface texture information, such as roughness, porosity, glazing, contamination, compressibility, and hardness, among others.

In one embodiment, the sensors 288, 294 may provide the controller 190 with signals that are resolved to indicate the usage, the amount of linear displacement, and condition of the polishing material 252 in the system, thereby allowing the controller to dynamically write and update information in the memory device 298. The updated and rewritten information in the memory device 298 allows the controller 190 to obtain the latest performance and condition of the polishing material 252, thus enhancing the process control and consumable material management. The signals between the controller 190 and memory device 298 may be provided by radio frequency transmission, optical communication, wireless transmission, hard wire or any other suitable means.

FIGS. 3A-B depict end and side views of one embodiment of the supply roll 240 of the polishing media assembly 274. In the embodiment depicted in FIG. 3B, the core 296 is a cylindrical body 310. The body 310 has an outer wall 302 and an inner wall 304 that defines a hollow passage 308 through the center of the core 296. In one embodiment, the body 310 includes a slot or a notch 306 that receives the memory device 298. The slot 306 may be in the inner wall 304, outer wall 302, or through the body 310. In another embodiment, the memory device 298 may be clamped, adhered, secured or fastened by other suitable materials to the core 296.

FIG. 4 depicts another embodiment of a memory device 298 coupled to a polishing media assembly 400. The polishing media assembly 400 may include a leader 272 connected to the beginning and/or end of the polishing material 252. In one embodiment, the memory device 298 may be mounted on or embedded in the leader 272 of the polishing material 252, as shown by phantom position 402. In another embodiment, the memory device 298 may be attached to or embedded in a portion of the polishing material 252, as shown by phantom position 404. It is contemplated that the ends of a polishing material without a leader may be fastened together to form a belt.

FIG. 5 depicts another embodiment of a polishing media assembly 500 having a memory device 298. The polishing media assembly 500 is in the form of a pad 502, for example, a circular pad. The memory device 298 is coupled to or embedded in the pad 502. In one embodiment, the memory device 298 may be embedded in an edge 506 of the polishing pad 502. In another embodiment, the memory device 298 may be embedded in a top portion or a bottom portion 508 of the polishing pad 502. In yet another embodiment, the memory device 298 may be attached on a bottom 504 of the polishing pad 502. In still another embodiment, the memory device 298 may be coupled to the exterior of the pad 502, for example, the edge 510.

The memory device 298 provides information relating to the polishing material 252 to the controller 190. As the memory device 298 being installed with the polishing media assembly 274 in the polishing system 100, the computer based controller 190 may sense the memory device 298 and read the information contained in the memory device 298, thereby allowing the system 100 to determine suitable parameters corresponding to the installed polishing media assembly 274. In one embodiment, the controller 190 may remotely detect and/or sense the memory device 298 by radio transmission, optical communication, wireless transmission, or other suitable methods. Alteratively, a connector may be provided on the platen 230 or polishing station 132 to facilitate communication with the controller 190 through wires.

Thus, the present invention provides a memory device coupled to a polishing material to provide information associated with the polishing material. Moreover, the memory device advantageously facilitates efficient management of the polishing material by dynamically communicating with a computer based controller in a polishing system, thereby enhancing a better control of the polishing performance, polishing material maintenance and process cost.

While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. 

1. A smart polishing media assembly, comprising: a polishing material; and a memory device coupled to the polishing material.
 2. The apparatus of claim 1 further comprising: a core having the polishing material wound thereon.
 3. The apparatus of claim 2, wherein the memory device is coupled to the core.
 4. The apparatus of claim 1, wherein the memory device is coupled to a leader of the polishing material.
 5. The apparatus of claim 1, wherein the memory device is a computer readable and writable device.
 6. The apparatus of claim 1, wherein the memory device is coupled to an exterior surface of the polishing material.
 7. The apparatus of claim 1, wherein the memory device is embedded in the polishing material.
 8. The apparatus of claim 1, wherein the memory device includes information relating to the polishing material, the information comprising at least one of length, thickness, brand, material type, sequence numbers or unique identification code stored thereon.
 9. The apparatus of claim 1, wherein the memory device includes historical use information associated with the polishing material stored thereon.
 10. The apparatus of claim 1, wherein the memory device includes conditioning information stored thereon.
 11. The apparatus of claim 1, wherein the polishing material is a web or belt.
 12. The apparatus of claim 1, wherein the polishing material is a pad.
 13. A polishing system, comprising: a polishing station; a polishing material disposed in the polishing station; a memory device coupled to the polishing material; and a computer based controller adapted to communicate with the memory device.
 14. The apparatus of claim 13, wherein the memory device is a computer readable and writable device.
 15. The apparatus of claim 13, wherein the memory device includes information relating to the polishing material, the information comprising at least one of length, thickness, brand, material type, sequence numbers or unique identification code stored thereon.
 16. The apparatus of claim 13, wherein the memory device includes historical use information of the polishing material stored thereon.
 17. The apparatus of claim 13, wherein the memory includes conditioning information relating to the polishing material stored thereon.
 18. The apparatus of claim 13, wherein the polishing material is a web or belt.
 19. The apparatus of claim 13, wherein the polishing material is a pad.
 20. The apparatus of claim 13 further comprising: a core having the polishing material wound thereon, wherein the memory device is coupled to the core.
 21. A method for using a smart polishing media assembly in a polishing system, comprising: reading information from a memory device coupled to a polishing material disposed in a polishing station; and polishing a substrate placed in contact with the polishing material.
 22. The method of claim 21, further comprising: writing information to the memory device relating to historical use of the polishing material.
 23. The method of claim 22, wherein the information written to the memory device is at least one of conditioning information, material polished, fluids used on the polishing material, life of the polishing material or remaining length of a web.
 24. The method of claim 21, further comprising: analyzing the read information; and determining if polishing should be commenced in response to the read information.
 25. The method of claim 21, wherein the step of reading information from a memory device comprises: reading information indicative of polishing material life.
 26. The method of claim 21, wherein the step of reading information from a memory device comprises: reading information indicative of an unused length of the polishing material.
 27. The method of claim 22, wherein the step of reading information from a memory device comprises: reading information relating to process fluids used on the polishing material.
 28. The method of claim 22, wherein the step of reading information from a memory device comprises: reading information relating to materials polished on the polishing material. 